Arrangement for directional receiving



April 22, 1930. HERZOG 1,755,180

ARRANGEMENT FOR DIRECTIONAL RECEIVING Filed June 5, 1924 RECEIVING APPARATUS INVENTOR MQF HERZOG Q/M Cfdw d A TORNEY Patented Apr. 22, 1930 UNITED rate are An tinnzoa'or BERLIN, Hawa ian-stems 'ro ensnnnscitarr its mantras-s aerial. An object of the TELEGRAPHIE M. B.- n., or Bnnmn, GERMANY, A ooaiona'ri'on or GER-MANY ARRANGEMENT non nrnno rronan ancnivme Application filed Jane 5, 19%, Serial No.

My invention relates to radio apparatus and more particularly to arrangements for directional receiving, comprising generally a directional aerial and a non-directional invention is to produce such an arrangement that will give the usual cardioid characteristic and that will be able to receive a plurality of different wave lengths with the same adjustment of the apparatus as to phase relation between the currents in the directional and nondi rectional aerials.

Other objects will be apparent from the,

in which:

different from one another.

known, depends places come from certain directions.

The single figure is a circuit embodying the invention.

One of the best known connections for directional receiving is the combination of are receiving systems, one of them being a closed frame aerial or a system of frame aerials and the other an open aerial. The currents of these two receiving systems act upon a third circuit in such a way that the amplitudes of these currents produced by the two receiving. systems are equal to one another and that the'phases are 0 or 180 The receiving characteristic of the frame aerial, as is wellon the cosine of the angle of the incoming waves, but the open aerial re- CBiVGS' equally Well from all directions. The resulting receiving characteristic of the combination of both systems is the well-known cardioid.

Such receiving arrangements are successfully used for eliminating atmospherics, as ithas been found that atmospherics at most The atmospherics coming from a certain direction' can easily beeliminated as the equal natural oscillations of both receiving systems-caused by the same atmospheric can be completely compensated if both aerial systems-have the same damping.

Acerial'combinations of the above described kind are chiefly used for eliminating disturbances caused by unda-mpedwave transmitterswhic'h do'not lie in the same direcby the drawing 717,914, and in Germany June 13, 1923.

tion as ceived. Up till now an aperiodic frame aerial has been frequently combined with an open aerial for obtaining a cardioid shaped receiving characteristic.

In order to be able to adjust the right phase diii'erence between open aerial current and frame .aerial current, it was always necessity that either the open aerial itself or the circuit coupled to this open aerial could be tuned. Consequently, the adjustment of the desired receiving characteristic is effective only forone certain Wave-length. The present invention relates to a method by which the effect of the open aerial can be nearly aperiodically transferred to the common receiving circuit. The required phase of the current caused by the open aerial can be adjusted without syntonization The principle of the invention is fully explained K is the entranc'e circuit of the radio frequency amplifier of the receiving apparatus, which is supplied by the effect of the open aerial and the effect of thejfra'me aerial having a phase displacement of 0 or 180 respectively. coil connected to the entrance circuit K. The energy induced in the open aerial circuit F is led to the input circuit of thermionic tube E, by means of coupling coils A,

In the usual former arrangements the ef-' fect of the open aei-i'al was lied to a syntonizing circuit by which the effect of the aerial current was transferred in right phase to the entrance circuit K of the radio frequency amplifier. As shown in the' drawing another arrangement is used according to'tli'e invention for adjusting the phase. I The energy acquired by the open aerial is led to the grid circuit of a' vacuum tube E the plate-filament circuit of which contains a self-inductance L and a resistance L serially connected. The voltage drop which can-be taken from this inductance and resistance has a phase relation to the plate-filament current of the vacuum tube and consequently with the aerial current acting on the grid of this vacuum tube according to the points. across" which the voltage drop the transmitting station to be re D is the frame aerial the alternating current component of the plate-filament current. If only the voltage drop across the self-inductance is used, its phase is 90 different from that of the current. Consequently any phase between 0 and 90 can be obtained by choosing the branching points 1 and 2 in such a way that a part of the inductance coil L as well as a part of the re-.

sistance L lies between lll'lQL This voltage is now led to the grid of-another vacuum tube 2 the plate-filament circuit directly by means of coupling coils B upon the entrance circuit of the radio frequency amplifier. By means of this adjustment of the phase a receiving characteristic is obtained which remains the same for a larger wave-scale. Of course this adjustment of phase according to the present method is not quite independent of the frequency as the voltage across the inductance coil comprises this frequency. The adjustment of the phase can remain unaltered for the wave AiAA, if AA is equal to 510% of A, in order to obtain the same direction finding characteristi of the arrangements. It is absolutely necessary to employ a coupling between two vacuum tubes in the present invention as the abovementioned resistance L used for the regulation of the phase must be very high. Such a high resistance can be inserted into the plate filament circuit of a vacuum tube because of the high internal resistance of this vacuum tube, but it would be practically impossible to use such a high resistance in a circuit which contains no vacuum tube. The different phase relations are shortly explained by the following:

If Ri is the internal resistance of the vacuum tube and Eg the grid voltage, the phase angle C of the alternating current Ia in the plate-filament circuit is given by:

where a) is equal to 21!- times the frequency.

If L is small in comparison with R2 and L Ia is approximately in phase with E9. Designating those parts of L and L which lie between the branching points 1 and 2 as Z and Z then the phase 1,0 of the used voltage in comparison with Ia is given by:

col

tan 0 of which acts The resistance L appropriately consists of a vacuum tube the apparent resistance of which (plate-filament) can be regulated by altering the voltage applied to the grid.

and a resistance and impedance in seriescommon to said circuits.

2. In combination, a tuned directional antenna and an. aperiodic non-directional antenna, means for coupling said antennae, comprising a circuit coupled to the directional antenna and a radio frequency amplifier coupled to the non-directional antenna, said amplifier having a resistance in its output common to the circuit coupled to the directional antenna.

3. In combination, a directional antenna and an aperiodic non-directional antenna, means for coupling said antennae comprising a circuit coupled to the directional antenna and a radio frequency amplifier coupled to the non-directional antenna, said amplifier having a reactance and a resistance in its output common to the circuit coupled to the directional antenna.

4. Incombination, a tuned directional and an aperiodic non-directional antennae, means for coupling said antennae comprising a circuit coupled to the directional antenna and a radio frequency amplifier coupled to the non-directional antenna, said amplifier hav ing a reactance and a resistance in its output common to the circuit coupled to the directional antenna, means adjustably associated with said reactance for regulating phase relation between said antennae.

5. In combination, a tuned directional and an aperiodic non-directional antenna, an amplifier, having grid and plate circuits, coupled to one antenna, reactances in the plate circuit, a second amplifier adjustably associated with said reactances whereby output phase relation may be varied with respect to remaining circuits.

6. In combination, a tuned directional and an aperiodic non-directional antenna, an amplifier, having grid and plate circuits, coupled to one antenna, reactances in the plate circuit, a second amplifier having an output circuit coupled to another antenna, adjustably associatedwith said reactances,

*coupled to one antenna,

whereby output phase relation may be varied with respect to remaining circuits.

7. In combination, a tuned directional and. an aperiodic non-directional antenna, an amplifier, having grid and plate circuits, reactances in the plate circuit, a second amplifier having an output circuit coupled to another antenna, adjustably associated with said reactances,

whereby output phase relation may be varied circuits, and a single tuning element for said directional antenna circuit.

8. In combination, directionaland non-directional antennae, a single tuning element associated with one of said antennae, and a with respect to remaining pair of coupling circuits between the antennae having a phase shifting means common to said circuits.

9. In a receiving device a tuned directional and an aperiodic non-directional antenna, means to lead the energy acquired by the said non-directional antenna to the grid circuit of a vacuum tube the plate circuit of which contains a self inductance in series with a resistance whereby a phase difierence may exist between the voltage drop across said inductance and resistance and the plate current of said vacuum tube and consequently with a non-directional antenna current, means comprising the grid circuit of a second vacuum tube circuit inductively coupled to the circuit of said directional antenna and a radio frequency amplifier for leading said Voltage to said directional antenna circuit.

10. In combination a tuned directional antenna circuit, an aperiodic non-directional antenna circuit, two Vacuum tube circuits and a receiving circuit, said last named circuit being coupled directly to said directional antenna circuit, inductive means for leading energy from said non-directional antenna circuit to the input side of one of said vacuum tube circuits, a resistance in series with a self inductance in the output side of said vacuum tube circuit and means in the input side of the other vacuum tube circuit comprising an adjustable connection to said self inductance and resistance for connecting the output side of the first named vacuum tube circuit to the input side of the second named vacuum tube circuit whereby the phase difference between the input sides of both of said circuits may be adjusted as desired.

ALF HERZOG. 

